Typewriter carbon sheet and attachment



Jan-3,1939. E..W.M.THOMSQN 2,14 76 I YPEWRITER CARBON SHEET AND ATTACHMENT Filed March 9, 1937 2 Sheets-Sheet l chine.

Patented has, 1939 UNITED STATES TYPEWRITER CARBON SHEET AND ATTACHMENT Edward William Mowat Thomson, Toronto, Ontario, Canada.

Application March 9,

1937, Serial No. 129,889

In Great Britain March 10, 1936 7 Claims.

This invention relates to carbon sheets and attachments for typewriters for use with what are known as fan-folded or superimposed webs of duplicating forms.

It is desirable in typing such forms to be able to use the same carbon sheets repeatedly and to so support and actuatethe sheets in the machine that they require no handling until they are worn out and require to be replaced. In my prior United States Patent No. 1,934,954, dated November 14th, 1933 I disclose an arrangement for this purpose substantially as follows: A guide is supported on the typewriter machine above the forward side of the platen and through this guide the superimposed webs of paper are passed with carbon sheets interleaved. The carbon sheets are wider than the webs and the margins are strengthened, as, for example, by applying 2. ply of stilfer tougher material thereto. In eachmargin adjacent the lower edge of each sheet is provided a dog-engageable shoulder, preferably formed as an aperture in the margin. On the guide are pivoted dogs adapted to engage the shoulders formed by these apertures when in the feeding of the webs over the platen the end of a. form has been reached. A fresh length of the webs can then be drawn up about the platen, while the carbon sheets are held by the dogs. The carbon sheets are thus positioned between a fresh set of forms after which the forms are brought back to the typing position by rotating the platen backwardly in the usual manner.

The dogs release themselves automatically from the apertures in the carbon sheets as the forms are thus moved and the carbon sheets travel back with the fresh forms between which they have been positioned when held by the dogs as the webs were drawn up as previously described.

This arrangement, it will be noted, necessitates.

the drawing up and out of the fresh lengths of webs while the carbon sheet is held by its bottom edge at the front of the platen and projecting with substantially its full length out of the ma- Under these conditions it demands a long stretch of the arms of the typist to draw the fresh lengths of the webs into alinement with the carbon sheet, particularly if the forms are long.

My object in the present invention, therefore, is to devise an arrangement which will overcome the objection to the earlier construction and enable the alinement of fresh lengths of the webs with the carbon sheet or sheets to be effected by the rotation of the typewriter platen.

I attain my object by means of the constructlon and arrangement of the parts I will now describe.

A guide for the webs and carbon sheet is pro-- vided which will be connected to share the lateral traverse of a typewriter platen to guide the webs and carbon sheets to the platen.

Either single carbon sheets may be used or a pack, such as hereinafter described, in which a number of carbon sheets are connected to a thin stiff flexible carrying strip having holes therein for engagement with keepers as hereinafter described, said carrying strip being preferably formed with projecting ends in which the holes are formed.

For fan-folded webs in which the webs are folded longitudinally so that the carbon sheets must be inserted from opposite sides, the trailing ends of the carbon sheets can only project at one side from between the webs and therefore each must be connected to the projecting end of the carrying strip at that side in such a manner that it cannot swing in the plane of the web surfaces between which it is located.

The guide is provided with a flat transverse cross bar adjustable lengthwise of the guide to suit diiferent lengths of the forms. Preferably behind the cross bar is journalled a hook shaft havinghook-shaped rock arms or keepers fixed thereon and adapted to be projected or retracted through holes in the cross bar. This rock shaft is spring pressed so that normally the hooks are projected so that the holes aforesaid may ride over and engage them. The shaft is also provided with manually operable fingers by means of which it may be rocked to retract the hooks.

The invention is illustrated in the accompanying drawings in which Fig. 1 is a plan view showing parts of a typewriter with my attachment in position;

Fig. 2 a. cross section on the line 2-2 in Fig. 1;

Fig. 3 a plan view partly broken away of a carbon sheet pack;

Fig. 4 a similar view of a modified form of the pack;

Fig. 5 an end view of Fig. 4;

Fig. 6 a. plan view of a single carbon sheet for use with my invention;

Fig. 7 a side View of Fig. 6;

Fig. 8 a. sectional detail showing a carbon pack engaging with the retaining hooks of the appliance; I

Fig. 9 a rear elevation of the movable cross bar of the apparatus and parts carried thereby; and

Fig. 10 a detail inside elevation of a kicker a 26 carbon sheets 24, each of which is provided atdevice for ensuring the disengagement of a caralso the lateral extensions in which the eyelet bon pack from the retaining hook.

In the drawings like numerals of reference indicate corresponding parts in the difierent figures. Referring to Figs. 1 and 2 of the drawings, i is the platen ofa typewriter, 2 the paper guide and 3 a cross bar of the carriage found in some machines. My applicance includes a guide frame 4 having side members l0 provided with'iaws I adapted to engage the bar 3 as shown.

The guide frame 4 is provided with the lower cross bar 9 on which the jaws I are formed. On the Jaws 5 are pivoted the hooks 6 serving as latches to hold the jaws in engagement with the cross bar 2. Each book is preferably provided with the clamp screw 1'. To the centre of the cross bar 9 is secured the arm I, which is adapted to rest against the paper guide 2, thus retaining to the cross bar 8' and at its ends is adapted to operate through openings in the sleeves to ensage in notches it formed in the side members it. Notches may be provided in the side members I. in different positions so that the cross bar 2' may be adjusted to suit different lengths of forms or for a purpose in relation to the carbon sheets which will appear hereinafter. On the cross bar 9 is journalled the rock shaft H which is provided with the hook shaped rock arms I! which operate through holes IS in the cross bar. The hook ends of these arms, it will be noted, normally extend forwardly and upwardly as shown and forms keepers.

At each end of the rock shaft i4 is formed a .manually operable finger ill by means of which spring thus normally holds the hooks in the projected position shown in Fig. 2 of the drawings. (izaxity positioned hooks might be employed ins a Slidable on the top bar 29 of the guide frame 4 are the side guides 20, which may be clamped on the top bar in any desired position by means of the set screws 2 I. These guides will be set to take the width of the forms being typed.

In Fig. 3 I show a carbon sheet pack. This comprises a stiff strip 22 which is of sufllcient length toextend beyond the edges of the forms to be typed. At each end of this stiff strip is formed an eye 23 for engagement with a hook ii. To this stiff strip are secured by dome fasteners each side with an extension 25, preferably stiffened, through which the dome fasteners 26 pass.

The carbon sheets are thus easily interposed between the form webs and secured to the stiff strip 22 when the forms are folded in the ordinary zig-zag manner. If forms are used which are longitudinally folded, then a carbon pack,

such as shown in Figs. 4 and 5, must be employed in which each carbon sheet is secured to a stiff adjustable on the guide to suit different lengths of forms. It may also be adjusted to suit different lengths of carbon sheets which may be reduced in length from time to time as they become worn. As most of the wear on the carbon sheets occurs where the names and addresses are imprinted, this portion of each carbon sheet may be cut of! and upon adjusting the cross bar fresh portions of the sheets will underlie the forms at the place where the addresses are typed. This shifting of the carbon sheets will also result in fresh portions of the sheets being positioned beneath that portion of the forms on which the accounts are typed.

I have shown and descrrbed one means of supporting the paper guide 2 so that it will share the lateral traverse of the typewriter carriage, but, of course, any other construction may be employed for this purpose, such, for example, as a known form, in which the guide frame runs on tracks at the back of the typewriter and is suitably connected with the typewriter carriage to move therewith.

It will be noted that the eyelets 22 form in effect shoulders to resist forward movement of the carbon sheet when the eyelets are engaged with the hooks andthe webs are being pulled forward.

It is preferred to apply a moderately stiff and flexible but thin back sheet 22 to the carbon sheet pack. This overlies the paper webs and serves to prevent buckling of the webs between the support frame and the paper guide of the typewriter when the platen is reversed. This back sheet preferably has the heads of the dome-fasteners 26 secured thereto and is thereby secured to the pack. It thus takes the place of the bail shown for this purpose in my prior United States Patent 1,934,954. v

Theoperation of the device is substantially as follows: Initially the carbon sheet or pack has the eyes 23 engaged with the hooks aforesaid and the webs of forms drawn down as may be necessary to aline a set of forms with the carbon sheet pack. The hooks will then be released by operating the fingers i9 and a first set of forms with a carbon sheet or sheets between will be passed through the machine and typed. The platen is then rotated by hand in the reverse direction to work back the paperand carbon sheets until the holes or eyelets at the sides of the carbon sheet or pack slip over and engage the hooks aforesaid to hold the pack stationary during the next operation, see Figs. 2 and 8 of the drawings. The platen is then rotated forwardly until a fresh set of forms is alined with a carbon sheet or pack and the typed forms are again projected at the front of the platen ready to be torn off.

The hooks are then retracted and typing the second set of forms can be proceeded with.

Thus at no time is it necessary to have more than a form's length of the webs projecting from the front of the platen.

It will be found that there is considerable economy in using packs such as described since the stiff strips with the eyes at each end can be used over and over while the carbon sheets can be easily replaced as needed.

It should also' be noted that though it is preferable that the holes for engagement with the keepers should be formed in lateral projections of the carbon sheets or carrying strips, yet it is possible to position them elsewhere along the strips or sheets for engagement with correspondingly placed keepers.

To ensure the disengagement of the hooks I! from the holes in the sides of the carbon sheet or pack, I secure to each finger IS a camlike kicker 3| which kickers engage the ends of the parts in which the holes 23 are formed and push the same downwardly, as the hooks are retracted, and in such a way as to ensure that, when the hooks return to their normal position they will not re-engage the shoulders formed by the holes.

What I claim as my invention is:

1. A continuous billing attachment for typewriters using travelling work webs and a carbon sheet or transfer means provided with forwardly facing shoulders adjacent its trailing end comprising a support for the work laterally movable with and behind the platen of the typewriter; and keepers on the support formed as spring-pressed normally projected hooks positioned for automatic engagement with the shoulders aforesaid, when the carbon sheet is moved backwards with the webs and is in retracted position relative to the platen, to thus hold the sheet against forward movement with the webs.

2. A continuous billing attachment according to claim 1 provided with manually operable means for retracting the hooks to permit the carbon sheet to be moved forward with the webs.

3. A continuous billing attachment according to claim 1 in which the support is provided with across bar on which the hooks are mounted and which is provided with holes through which the hooks operate.

4. A continuous billing attachment according to claim 1 in which the support is provided with a cross bar having holes therein through which the hooks operate, a rock shaft to which the hooks are connected and a rock arm connected to the shaft whereby it may be rocked by hand 'to retract the hooks.

5. A continuous billing attachment according to claim Lin which a cross bar is provided longitudinally adjustable of the work support and 'on which the hooks are mounted.

6. A continuous billing attachment according to claim 1 in which the carbon transfer means is provided with holes engageable with the hooks.

7. A continuous billing attachment according to claim 1 in which the support is provided with a rock shaft to which the hooks are connected,

a rock arm connected to the shaft whereby it 

